package org.apache.lucene.analysis.tokenattributes;

/**
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import java.io.Serializable;

import org.apache.lucene.index.Payload;
import org.apache.lucene.util.AttributeImpl;

/**
 * The payload of a Token. See also {@link Payload}.
 */
public class PayloadAttributeImpl extends AttributeImpl implements PayloadAttribute, Cloneable, Serializable {
    private Payload payload;

    /**
     * Initialize this attribute with no payload.
     */
    public PayloadAttributeImpl() {
    }

    /**
     * Initialize this attribute with the given payload. 
     */
    public PayloadAttributeImpl(Payload payload) {
        this.payload = payload;
    }

    /**
     * Returns this Token's payload.
     */
    public Payload getPayload() {
        return this.payload;
    }

    /** 
     * Sets this Token's payload.
     */
    public void setPayload(Payload payload) {
        this.payload = payload;
    }

    @Override
    public void clear() {
        payload = null;
    }

    @Override
    public Object clone() {
        PayloadAttributeImpl clone = (PayloadAttributeImpl) super.clone();
        if (payload != null) {
            clone.payload = (Payload) payload.clone();
        }
        return clone;
    }

    @Override
    public boolean equals(Object other) {
        if (other == this) {
            return true;
        }

        if (other instanceof PayloadAttribute) {
            PayloadAttributeImpl o = (PayloadAttributeImpl) other;
            if (o.payload == null || payload == null) {
                return o.payload == null && payload == null;
            }

            return o.payload.equals(payload);
        }

        return false;
    }

    @Override
    public int hashCode() {
        return (payload == null) ? 0 : payload.hashCode();
    }

    @Override
    public void copyTo(AttributeImpl target) {
        PayloadAttribute t = (PayloadAttribute) target;
        t.setPayload((payload == null) ? null : (Payload) payload.clone());
    }

}
